What do you mean by "NTLM users not getting resolved?" Do you have both Windows and FBA set up on the same web application, or did you extend the web application to support one of the authentication providers? If both providers are configured on the same web app, do you see the default sign-in page that lets you choose between Windows and Forms Authentication when you click "Sign In?"
–
Danny JesseeMay 29 '12 at 20:38

Ya.. I have setup both on the same web application and I do have a default sign-in page.
–
StriderMay 30 '12 at 3:01

I assume you're choosing "Windows" and not "Forms" when you want your AD users to log in? Are you attempting to log in on the SharePoint server itself or from other client machines? Are you seeing any 401 or other errors in the IIS logs from failed AD logins?
–
Danny JesseeMay 30 '12 at 10:04

ya... I am using windows authentication to signin AD users. I will signin the default sign in page of SharePoint. I did not have 404 error.. but like the user name are not recognised in SharePoint
–
StriderMay 30 '12 at 11:38

Can you provide a screen shot of your web application authentication providers - particularly the Windows and forms based authentication sections? Please also you share your web.config for this web application? Are you using a single server or multiple?
–
James CallaghanJan 5 '14 at 12:46

I have configured the fba properly... Only issue is AD users are not shown up... I had tried the same config in another system where it works fine... I think it may be because Service Packs are not installed in my machine.
–
StriderMay 29 '12 at 17:03

What do you use to login to central admin? your FBA account or your AD account?
–
Felipe KettleMay 31 '12 at 17:04

have you checked that the authentication providers for each zone are setup correctly? (central admin).. I don't have a SharePoint site in front of me but here is what I would check...
A- has the server lost connection to AD?
B- authentication providers setup correctly for the zone which the alternate access mapping is configured on.
C- that you have extended web app from windows auth to forms auth rather than the other way round